1. Field of the Invention
The present invention generally relates to returnable shipping containers, and more specifically to returnable shipping containers having drop down doors to permit access to goods contained in such containers.
2. General Background of the Invention
For many years, industries dealing in bulk goods have utilized returnable containers. Such containers typically have one or more drop-down doors located in the sidewalls of the container to permit operators easy access to the interior of the container to load goods into or unload goods from the container. Such drop-down doors are typically hinged at the bottom and held in an upright position using a pair of latches located on the vertical sides of the door. Frequently the mating hinge knuckles are formed integrally with the container sidewall and the drop-down door. A hinge pin is then inserted to bear the load of the door and to establish the axis of rotation.
In practice, operators will frequently unlatch the door and then allow it to freely rotate to its open position. This practice can, however, lead to injuries to the Operator if the hinges are not properly installed or assembled or if the hinges fail. In such cases, the door can freely fall to the floor, possibly causing injury to the operator. Such issues may not be obvious to an operator in advance, however, because a door installed in its upright, closed position will typically rest on the sidewall and have a lip or similar feature along its bottom portion that impinges on the inside of the sidewall to assist in bearing the load of the goods loaded in the container. Thus, a hinge issue is unlikely to be noticed in a door that is latched in its upright position because the latches and the lip cooperate to keep the door in place.
Previous attempts to address this issue have involved the use of a flexible safety tether in an attempt to keep door 50 from falling freely to the floor. The use of tethers, however, creates other issues that are not conducive to an efficient and safe workplace. For example, if the tether is located on the inside of the container, it can become tangled in the goods. And if the tether hangs on the outside of a container, it can be become tangled with other containers, which can create a hazard, especially where containers are stacked on top of one another in tight stacks. The productivity of operators can also be impacted by tethers since such tethers can get in the way of operators as they load and unload containers.
What is needed then is a returnable bulk container with a mechanism to prevent a drop-down side door from separating from the container in the case of a hinge failure that does not involve the use of a tether.